Viana do Castelo Weather in September
In Viana do Castelo, September brings high daytime temperatures around 22°C (72°F), with nights cooling to 16°C (61°F). Expect quite a bit of rainfall this month.
Rainfall in Viana do Castelo in September
Typically around 10 days of rainfall are expected, averaging 84 mm (3.3 in) for the month. When showers do arrive, they tend to be on the heavier side. Worth being prepared even if rain days are not that numerous.
Temperature in Viana do Castelo in September
September is a good time to be in Viana do Castelo. Days are perfect, reaching 22°C (72°F), with nights around 16°C (61°F). September is in the summer season. The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. Nights drop to around 16°C (61°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.
Sunshine in Viana do Castelo in September
The days are predominantly sunny, with an estimated total of around 224 hours of sunshine. These sun-filled days are perfect for playing sports, visiting parks, or going for a bike ride.If your ideal day consists of dry skies and pleasant temperatures, June, July, August and September typically offer the best circumstances for Viana do Castelo.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Portugal, check out our Viana do Castelo's climate page.
Viana do Castelo Temperature in September
Min Temperature
16°C (61°F)
Max Temperature
22°C (72°F)
Chance of Rain
33%
Precipitation
84 mm (3.3 in)
Rainy days
10 days
Humidity
76% *
Sunshine
224 hours *
Percentage Sunshine
64% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Viana do Castelo typically stay consistent throughout September, with daily highs averaging around 22°C (72°F). Nights are cool, with lows typically ranging from 13°C (55°F) to 15°C (59°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Viana do Castelo in September
Browse day-by-day weather records for Viana do Castelo spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Viana do Castelo historical weather extremes in September
The extremes listed below come from historical weather data collected in Viana do Castelo from 1976 through 2025.
- The warmest day in September was on September 6, 1983, with a maximum of 36°C (97°F).
- The coldest September day was on September 26, 1992, with a maximum of 15°C (59°F).
- The lowest overnight temperature recorded in September was 6°C (43°F) (September 18, 1976).
Best Places in Portugal in September
Find out more about the weather in Portugal and which places have the best travel conditions in this month. See all of Portugal in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Viana do Castelo in September
Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Prepare for significant rainfall with proper waterproof clothing and shoes. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in Viana do Castelo in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Portugal, check out our Viana do Castelo's climate page.
Temperature Rainfall Sunshine Humidity
See the full Viana do Castelo climate overview or explore weather in Portugal.
